1. Field of the Invention
This invention relates to a concrete wall form assembly, or system, and method of assembling same and, more particularly, to such a concrete wall form assembly which is adapted for portability.
2. Description of the Related Art Including Information Disclosed Under 35 CFR 1.97-1.99
Concrete wall form assemblies comprising a plurality of interconnectable plywood panels or form walls which are interconnected at the job site to make a wall form are well known. Because of the substantial hydrostatic pressure of wet premixed concrete tending to forceably separate opposed sections of a concrete wall form, it is known to provide mechanisms to tie together the opposed walls to resist form wall separation. The hydrostatic pressure also tends to flex, or bow out, the form walls or form wall panels, and for this reason it is known to reinforce the form wall panels against bowing with elongate metal braces. After the concrete has been set, the concrete wall form is disassembled and moved for reuse at another job site.
All of these known concrete wall form systems suffer from one or more disadvantageous features with respect to the assembly of the tie mechanisms, the presence of movable parts which can break, the presence of loose parts which can be lost and excessive weight.
In some systems, the opposed wall sections are held together by numerous elongate ties located intermediate the ends of the sections and distributed across the surface such that two persons on opposite sides of the opposed sections are required to align and thread the ties through mating tie holes in the wall sections. It is not possible for one person to perform the assembly in this system. In another system, the ties are locked against removal by special cam locking parts which are not permanently connected to the wall sections or to the ties and can be lost. In another known system, the ties have loops through which must be threaded, steel reinforcing rods to position removal of the ties and which are also separable from the wall sections constitute loose parts which can be easily lost or misplaced when needed.
In a third known system, the ties are accessible at the edges of the form wall section but require a special steel pivotal locking mechanism at the ends of elongate steel braces fixedly mounted to the wall sections for holding the ties against separation from the form wall sections; the ties are necessary to interconnect contiguous sections, so it is not possible to mount the form wall panels end to end without simultaneously tying together the opposed parallel form wall panels.
Other problems associated with known concrete wall form systems are associated with the need to provide the wall forms with substantial rigidity to resist bowing in response to the hydrostatic pressure of the wet concrete. The functional requirement of strength has been achieved in all known form wall systems at the expense of excessive weight, excessive costs, or both. In the one system without braces, 11/2 inch thick plywood is used to obtain the needed strength, but this causes excessive weight. In systems with metal braces, the thickness dimension of the braces is not elongate in a direction extending transversely away from the wall section for maximum resistance against bowing, and thus weight in the plywood and brace combination remains excessive. It is known to make form wall sections of all aluminum using aluminum frames but, because of the relative weakness of aluminum, excessive weight in the plywood and aluminum frame still results.